Torque converting apparatus



March 15, 1960 A. M. MAROTH TORQUE CONVERTING APPARATUS Original meMarch 13, 1957 s sheds-sheet 1 INVENTOR.

ARTHUR M. MAROTH 7 BY ATTORNEYS March 15, 1960 A. M. MAROTH TORQUECONVERTING APPARATUS Original Filed March 13, 1957 5 Sheets-Sheet 2Fig.3

INVENTOR.

ARTHUR M. MAROTH BY 6 ATTORNEYS March 15, 1960 A. M. MAROTH 2,928,289

TORQUE CONVERTING APPARATUS Original Filed March 13, 1957 5 Sheets-Sheet3 1 j /& Ix

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J M W -22 24a. QQ f uwuvrox ARTHUR M. MAROTH ATTORNEYS A. M. MAROTHTORQUE CONVERTING March 15, 1960 APPARATUS 5 Sheets-Sheet 4 OriginalFiled March I VENTO ARTHUR M.

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ATTORNEYS March 15, 1960 A. M. MAROTH 2,928,289

TORQUE CONVERTING APPARATUS Original Filed March 13, 1957 5 Sheets-Sheet5 7k i ulg v Q; Al

mmvrox ARTHUR M. MAROTH ATTORNEYS Unite Sttes Patent TDRQUE CGNVERTINGAPPARATUS Arthur M. Mar-th, Wilton, Conn.

Original application March 13, 1957, Serial No. 645,743,

now Patent No. 2,836,985, dated June 3, 1958. vDivided and thisapplication April 18, 1958, Serial No. 729,432

8 Claims. (Cl. 74-424.8)

This invention relates to a transmission or torque converterconstruction. More particularly, the invention has to do with a screwand nut construction to convert efficiently rotary motion of the nutinto linear motion of the screw. This application is a division of myoriginal application, Serial No. 645,743, filed March 13, 1957, whichissued as Patent No. 2,836,985 on June 3, 1958.

One of the objects of this invention is to provide a torque converterconstruction which is simple and thoroughly reliable and practical inoperation. Another object is to provide a torque converter of the abovecharacter which is markedly efiicient in operation, thus reducing: to aminimum the loss factor in power conversion. Another object is toprovide a torque converter construction of the above character wherein ascrew and nut construction is utilized to facilitate easy rotary motioncombined with a highly efiicient transfer factor to linear motion of theshaft. Another object of this invention is to provide a torque converterconstruction of the above characterwherein certain friction-eliminatingelements are combined with the usual screw and nut construction toachieve a ready and efficient transfer from rotary to linear force. isto provide construction of the above character which is essentiallysimple and depends in a large part on readily available standard partsso that the manufacture thereof is easy and economical. part be obviousand in part pointed out hereinafter.

The invention accordingly comprises features of construction,combinations of elements, and arrangements of parts, which will beexemplified in the construction hereinafter set forth, and the scope ofthe invention will be indicated in the claims to follow.

Another object of this invention Other objects will in For a fullerunderstanding of, the nature and objects of: the invention, reference.should be had to the following detailed description taken in connection,with the accomits starting position,

Figure 5 is a view similar to Figure 4 of the same parts at an.intermediate stage in the operation of the co-nverter construction,

Figure 6 is a view similar to Figures 4 and 5 showing the mechanism asthe operation progresses to a final phase of the operative sequence,

Figure 7 is a horizontal sectional view taken along the line 7--7 ofFigure 1,

Figure. 8 is a horizontal sectional view taken along the line 8;--8 ofFigure 1 and Fatgented Mar. 15, 1%66 ice Similar reference charactersrefer to. similar partsv throughout the several views of the drawings.

Generally speaking, the mechanism comprises. a nut member generallyindicated at 10 consisting of three seg ments 12', 14 and 16 andassociated mechanism secured together by screws 18 and 20, all as can beseen in Figure 1. Segments 12, 14 and 16 are concentric with but notthreaded on a screw shaft generally indicated at 11.; however, the nutmember as a unitary mechanism is threaded on the shaft by way ofmechanism. associated therewith to be presently described. Nut member1.0. rests on roller bearings 13 supported on. a base 15 and shaft 11extends through a hole 17 therein. Furthermore, nut member 10 isrotatably supported on shaft 11 by roller bearings 19 and 23. Theconstruction to be described is designed to move shaft 11 upwardlyagainst a downward force indicated by the arrows in Figure 1. Stationaryring cam plates 26, and 28. are disposed immediately above rotary camplates 22 and 24', respectively, and interposed between these pairs ofcam, plates are sets of balls 30 and 32. respectively. Further, camplates 22' and 24 are connected to segments 14 and 16., respectively,of. nut member 10 by suitable inter-fitting parts (not shown) therebyassuring that these parts will; always move in unison. Cam plates 26and, 28 are keyed to shaft 11 by way ofua key way generally indicated at2-3, in Figure 1A. Thus, cam plates 26 and 28 are, free to slidelongitudinally with. respect to. screw shaft. 11 in a manner to bepresently described. Thus, as can be understood from Figures 1-6, balls30. and 32 are disposed to roll. between the cam surfaces of these pairsof cam plates; more particularly, balls 30, held in a retainer ring 34',are disposed between rotary cam plate 22 and stationary cam plate, 26,while. balls 32 are held in a retainer ring 36 between cam plates 24 and28.

Nut members 38. and 40: are disposed immediately above cam plates 26 and28,. respectively, and are threaded on screw shaft. 11 which is adaptedto be driven upwardly against the downward force as indicated by thearrows in Figure lby the camming action to be described. Figures 4, 5and 6 indicate a sequence of movements between cam plates 22 and 26during rotation of nut in, and cam plates 24. and 23 are identical. inconstruction but oppositely disposed so that, they highs on the camsurfaces. of one, pair of. cam plates. oppose each; other when the lows:in the other set of cam plates. are optpo-site each other. Moreparticularly, when cam plates 22 and 26 arein position shown in Figure4, cam plates 24 and 28- will occupy the position of Figure 6 and in theoperation to be presently described, it is assumed that these parts arein such positions.

Referring to Figure 1, stationary cam plates 26 and 28have extensions 44and 46 extending radially therefrom, extension 44 being better seen inFigure 2. Shafts 5% and 5d are rotatably mounted therein, shaft 48carrying pinions 52 and. 54. and shaft 5t} carrying similarly disposedpinions 56 and 58. Rotary cam plates 22 and 24 carry gear rings 60 and62, respectively, keyed thereto and meshing with pinions 52 and 56,while nut members 38 and 4t carry substantially similar gearrings 64 and6d meshing with pinions S4 and 58. Consequently rotation of cam plates22 and 24' rotates pinionsv 52 and S6, and by way of shafts 48 and 5t),pinions 54 and 58. This rotation causes corresponding movement. of gearrings 64 and 66 to rotate nut members 38 and. 40. As

can be seen in Figure 7, pinion 54 has teeth on less than of itssurface, and it is positioned on shaft 48 to be out of mesh with gearring 64 at the start of the operation to be described.

It will now be understood that clockwise movement of nut as viewed inFigure 1A moves rotary cam plates 22 and 24 correspondingly or to theleft as viewed in Figures 4-6. Considering for the moment the action ofcam plates 22 and 26 and associated parts, during movement from theposition shown in Figure 4 to the position shown in Figure 6, the highson the cam plates move from opposing positions to positions opposingballs 30. This causes vertical movement of nut member 38 which isconnected to shaft 11, and, consequently, the shaft moves upwardly. Aspreviously noted cam plates 24 and 28 were in the opposite or Figure 6position at the start of this operation. Thus the toothed portion ofpinion 58 was in mesh with gear ring 66. Accordingly, rotation of thenut member 16 rotates gear ring 62 and through pinions 56 and 58 nutmember 40 is threaded to and rotates about shaft 11. Therefore, nutmember 40 is in substantial engagement with cam plate 28 as the shaftmoves upwardly and will remain so as nut member 40 rotates on shaft 11.However, when balls 32 reach the low or Figure 4 position, balls 30 willhave reached the high or Figure 6 position and the action will reverse.More particularly, at this instant pinion 58 will demesh from gear ring66 and pinion 54 will mesh with gear ring 64. Continued rotation of nutmember 10 now causes cam plate 24 and associated mechanism to move shaft11 upwardly while nut member 38 rotates, because the toothed part ofpinion 54 has now meshed with gear ring 64. And so the action continuesas long as the nut member is rotated, the load alternately shifting fromone set of cam plates to the other during continuous operation and theslack being taken up by the nut members 38 and 40 alternately.

It is to be noted that during operation balls 30 and 32 must rollbetween the cam plates. Thus balls 30 rotate between cam plates 22 and26 and balls 32 likewise rotate between cam plates 24 and 28. Becausecam plates 26 and 28 are stationary with respect to rotating cam plates22 and 24, the linear movements of the centers of the balls is half thedistance traveled by the plates 22 and 24 with respect to plates 26 and28, respectively. Accordingly, to provide for proper movement of theretainer rings 34 and 36, the toothed peripheral faces 34a and 36athereon mesh with pinions 68 and 70, respectively, fixed to shafts 48and 50. These pinions 68 and 70 are so proportioned as to drive rings 34and 36 at half the speed of gear rings 60 and 62.

The cam surfaces of cam plates 22, 24, 26 and 28 are substantiallyidentical, and accordingly a description of the surfaces of cam plates22 and 24 as represented in Figures 4, 5 and 6 will sufiice for bothsets of cam plates. Thus, surfaces 24a and 24b as shown in Figures 4, 5and 6 are exactly complementary. In other words, the points of contactbetween the balls and cam surfaces 24a and 24b are at all times inparallel relationship. Stated in another way, a line x (Figures 4, 5 and6) drawn diametrically from contact points a and b on cam surfaces 24aand 2415 will at all times be normal to the respective surfaces beingcontacted. Because of this parallel relationship, there can be nosliding action between the balls and the cam surfaces. Consequently, allmotion is confined to rotary motion of the balls as they roll over therespective cam surfaces. Because there is no such sliding motion,friction is reduced to a minimum, and the cam plates will always bemaintained in proper complementary relationship, thereby to effectivelyconvert the rotary motion of the nut into vertical motion of the uppercam plates 26 and 28.

During operation nut members 38 and 40 must continuously move relativeto ring cam plates 26 and 28. In order to avoid frictional dragtherebetween, the teeth on pinion 54 cover less than 180 of theperiphery thereof. Accordingly, pinions 54 and 58 do not mesh with gearrings 64 and 66 at the transition point, i.e., when one set of the balls38 and 32 is in the high position (Figures 4-6) and the other in the lowposition. Rather the meshing of these gear parts takes place momentarilythereafter so that downward movement of the nut members with respect tothe shaft 11 does not precisely correspond to similar movement of camplates 22 and 24 which are following the balls as described above.

It will now be apparent that I have provided apparatus for transferringthe rotary motion of nut member 10 into the linear motion of shaft 11 ina markedly etficient manner. It will be noted that this transfer isconcentrated entirely in the rotary-cam action of the balls 30 and 32between the cam plates 22 and 26, and 24 and 28, respectively. Thisrolling action which constantly cams shaft 11 upwardly during rotationof the nut 10 therefore provides an effective transfer of these forceswith an absolute minimum of friction. It should be further noted thatthe pinion-drive connection between the cam plates 22 and 24 and the nutmembers 38 and 40 only operates in a resetting capacity, i.e., when thenut members are moving downwardly with respect to shaft 11 as viewed inFigure l and hence are under no load. Thus this piniondrive innerconnection takes no part in the actual torque transfer; otherwiseconsiderable frictional drag would be added.

In Figure 9 there is shown another embodiment of my invention in whichthe rotary motion of a shaft-72 is converted into rotary motion of agear wheel 74 keyed to a shaft 75. Thus, shaft 72 is rotatably mountedin a casing generally indicated at 76, and a pair of pinions 78 and 80fixed thereto mesh with the toothed peripheries of cam plates 82 and 84.Cam plates 82 and 84 are part of cam-ball torque converter mechanismsgenerally indicated at 86 and 88. These mechanisms are identical withthose previously described with reference to Figure 1, and they arerotatably mounted in casing 76 by way of roller bearings 90 and 92. Camplates 94 and 96 of mechanisms 86 and 88, respectively, engage flanges98 and 100 of reciprocating members generally indicated at 102 and 104,respectively. Thus, member 102 includes a shaft portion 106 reciprocablymounted in casing'76 and a socket portion 108 having grooves 109 formedtherein meshing with the teeth 110 on gear wheel 74. Member 104 includesa shaft portion 112 reciprocably mounted in casing 76 and an extension114 fitting within socket portion 108 and having an enlarged section 116with grooves 118 also meshing with teeth 110.

Accordingly, upon rotation of shaft 72, cam plates 82 and 84 are rotatedand through the action of cam-ball mechanisms 86 and 88 previouslydescribed, reciprocating members 182 and 104 are alternately urgeddownwardly as viewed in Figure 9, thereby continuously rotating gearwheel 74. It will be understood that by incorporating suitable changes,including roller bearings similar to bearings 90 and 92 interposedbetween flanges 98 and 108 and the casing 76, gear wheel 74 could bedriven in either direction according to the direction of rotation ofdrive shaft 72. It will also be understood that other types of wormelements or other grooved members, such as toothed racks, may be adaptedto perform the functions of reciprocating elements 192 and 194.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efficiently attained and,since certain changes may be made in the above construction withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawings shall be interpreted as illustrative and not in a limitingsense.

I claim:

1. In apparatus of the character described, in combination, a casing,two toothed members slidably supported in said casing, a gear wheelrotatably mounted in said casing and having its teeth in mesh with theteeth of said toothed members, and means for separately reciprocatingsaid toothed members axially to drive said gear wheel, said meansincluding at least one pair of annular cams acting upon each of saidtoothed members, each of said pairs of cams having their opposingadjacent faces provided with wavy surfaces, rolling members interposedbetween said wavy surfaces, and a cage for said rolling membersinterposed between each of said pairs of cams, said wavy surfaces beingso shaped that their opposing zones of contact with said rolling memberswill at all times be substantially oppositely disposed along diametersof said rolling members.

2. In apparatus of the character described, in combination, a casing,two grooved members slidably supported in said casing, a gear wheelrotatably mounted in said casing and having its teeth in mesh with thegrooves of both of said grooved members, and means for separatelyreciprocating said grooved members axially to drive said gear wheel,said means including at least one pair of annular cam plates acting uponeach of said grooved members, each of said pairs of cam plates havingtheir opposing adjacent faces provided with wavy surfaces, rollingmembers interposed between said wavy surfaces, driving means forcontinuously rotating the first of said cam plates in each pair, a cagefor said rolling members interposed between said cam plates, and meansinterconnecting the cam plates of each pair for alternately rotatingeach of the second of said cam plates, said wavy surfaces being shapedso that their opposing zones of contact with said rolling members willat all times be substantially oppositely disposed along diameters ofsaid rolling members.

3. The combination of claim 2 in which said interconnecting meanscomprises a pinion shaft bearing pinions meshing with teeth formed inthe periphery of each of said cam plates, one of said pinions meshingwith the second of said cam plates in each pair and having teeth on notmore than 180 of its circumference.

4. The combination of claim 3 in which said driving means includesdriven pinions meshing with the peripheral teeth of the first of saidcam plates in each pair.

5. In apparatus of the character described, in combination, a casing,two partially threaded shafts slidably mounted in said casing, a gearwheel having its teeth in mesh with the threads of both of said shaftsand rotatably mounted in said casing, each of said shafts having anannular extension, two first annular cam plates rotatably resting onsaid extensions, two second annular cam plates interposed between saidcam plates and said casing to form two pairs of cam plates, the opposingadjacent faces of each pair of said cam plates having wavy surfaces, aplurality of rolling members interposed between said wavy surfaces, acage for said rolling members interposed between said surfaces, saidwavy surfaces being so shaped that their opposing zones of contact withsaid rolling members will at all times be substantially oppositelydisposed along diameters of said rolling members, said diam-v etersbeing substantially normal to said zones of contact,

means mounted in said casing for rotatably supporting said second camplates, driving means for continuously rotating each of said second camplates, and means interconnecting the cam plates of each pair andactuated by said driving means for alternately rotating each of saidfirst cam plates, whereby said shafts are alternately recip' rocated todrive said gear wheel.

6. In a torque converter, in combination, a hollow casing, a threadedshaft mounted in said hollow casing and having a stud projection, athreaded'sleeve shaft mounted in said hollow casing coaxially with saidthreaded shaft and interfitting with said stud projection on saidthreaded shaft, a gear wheel rotatablymounted in said casing and havingits teeth in mesh with the threads of both of said shafts, each of saidshafts having an annular flange; two first annular cam plates rotatablyresting respectively on each one of said flanges, two second annular camplates interposed between said first cam plates and said casing to formtwo pairs of cam plates, the opposing adjacent faces of each pair of camplates having wavy surfaces, said surfaces having equally spaced radialtroughs and crests; a number of balls interposed between each of saidpairs of cam plates, said number of balls being no more than the numberof troughs in said surfaces, said wavy surfaces being shaped so thattheir opposing zones of contact with said balls will at all times besubstantially oppositely disposed along rolling diameters of said balls,said diameters being substantially normal to said zones of contact,thrust bearings mounted in said casing for rotatably supporting saidsecond cam plates, driving means for producing continuous rotation ofeach of said second cam plates, and means interconnecting the cam platesof each pair and actuated by said continuous rotation for alternatelyrotating each of said first cam plates, whereby said shafts arealternately reciprocated to drive said gear wheel.

7. The combination of claim 6 in which said interconnecting meanscomprises a pinion shaft bearing pinions meshing with teeth formed inthe periphery of each of said cam plates, one of said pinions meshingwith the second of said cam plates and having teeth on not more than ofits circumference.

8. The combination of claim 7 inswhich said driving means includesdriven pinions meshing with the peripheral teeth of the first of saidcam plates in each pair, said driven pinions being mounted upon a singledriven shaft.

References Cited in the file of this patent UNITED STATES PATENTS2,151,094 Fiorentino Mar. 21, 1939 2,583,775 Hyde Jan. 29, 1952 FOREIGNPATENTS 800,260 France July '1, 1936 862,470 France Mar. 7, 1941 FranceNov. 13, 1951

